Exercise is the best medicine for getting a good night's sleep

Working out is going to make sleep come more easily and deeply. You might just want to wait till you're done.

Working out is going to make sleep come more easily and deeply. You might just want to wait till you're done. (Mie Ahmt, Getty Images)

James S. FellChicago Tribune

Exercise means a good night's sleep

Since my wife and I moved in together 23 years ago, I've been waking up on the wrong side of the bed, because she took my side!

Nevertheless, for 21 of those years, I've been a regular exerciser and rarely make it past three pages in a novel before my eyes close, and — barring a child with a nightmare — they usually stay closed all night.

But many Americans have trouble when horizontal. Just this year the U.S. Centers for Disease Control and Prevention labeled insufficient sleep as a public health epidemic. It leads to car crashes, industrial accidents, poor work and school performance, and poor health. Those suffering from insufficient sleep are more likely to have diabetes, depression, hypertension, obesity, cancer and increased mortality rates. With 50 million to 70 million Americans not getting enough sleep, "epidemic" is an appropriate label.

There also is an epidemic of inactivity, and it's pretty obvious the two are linked. While sedentary living is associated with higher obesity, so is lack of sleep.

"There is evidence to suggest that decreased sleep may decrease basal metabolism," Dr. Sue Pedersen, a specialist in endocrinology and metabolism in Calgary, Canada, told me. Pedersen said acute sleep deprivation lowers core body temperature, which lowers daily caloric burn. What's more, we're less likely to fidget or engage in any type of physical activity when tired, which means even fewer calories burned. "We're more likely to find ways to cut corners on activity when we're tired," Pedersen said.

That's the obvious aspect, but hormones play a role as well.

"There are also a number of hormones that have been found to be affected by sleep deprivation," Pedersen explained. Leptin is lowered, and this is a concern because this hormone stimulates energy expenditure and tells us when we're feeling full. If you're battling your weight, low leptin is bad.

"We also see higher levels of grehlin in shorter sleepers," she said. "This increases the sense of hunger and the desire to eat." Willpower to make healthy eating decisions also is compromised. In addition, Pedersen said, poor sleep leads to more screen time (TV, computer, gaming), which is shown to prompt unhealthy snacking. A 2012 study of a dozen men published in the Journal of Clinical Endocrinology and Metabolism found that a single night of acute sleep deprivation altered the way the brain reacted to the stimulus of treat foods, enhancing their desire to eat it.

And this doesn't refer to dramatic sleep deprivation. "We're talking about the levels of sleep loss that many people suffer from on a regular basis," Pedersen said. "These are regular society levels of sleep deprivation."

The link to obesity seems clear.

"Studies that show that children with short sleep are three times more likely to be overweight," Pedersen said. "This is 5-6 hours compared to 7-8 hours, so we're not talking about a big difference." She explained that it's a U-shaped curve, with too much sleep also being bad and that optimal levels are 7-8 hours for adults.

But what role does exercise play in stacking more high quality Zs?

"Exercise on a regular basis provides a strong signal to our circadian clock, especially if we exercise at a regular time every day," said Kathryn Reid, a neurology professor at Northwestern University in Chicago. She explained that exercising outdoors provides an added bonus, because of the positive benefit of getting some sun. "Light is perhaps the strongest synchronizer of the circadian system and it affects alertness and mood, which also affects your ability to sleep."

Speaking of mood, Pedersen said a primary benefit of exercise in improving sleep is stress management. "It makes you feel more relaxed," she said. This is a subject I've written about before, and there is ample research showing physical activity as being a very effective stress-reduction tool.

"A study we did on older adults saw significant improvements in mood and quality of life," Reid told me, "and that was associated with significant improvements in sleep quality." The study of 17 sedentary people over 55 who suffered from insomnia was published in Sleep Medicine in 2010. Numerous other research studies show a positive link between regular activity and sleep duration and quality.

"We know people who exercise are more likely to have good sleep," Pedersen said. "Evolution did not design us to sit inside an office all day. We've been programmed to be roaming around outside hunting and gathering and being physically active." Without regular movement, we're too wound up to sleep properly. In addition to the stress reduction, tiring yourself out is an important consideration.

Reid mentioned a study showing that athletes who take a break from exercise lose sleep. It makes sense that when you train your body to expend a lot of energy during the day that taking it easy could result in an energy surplus that makes for nocturnal tossing and turning.

While I've found being a regular exerciser to be beneficial to my own sleep habits, competition wreaks havoc. The night before my first marathon, I was so nervous I barely got two hours of sleep (but still made my time). And after qualifying for the Boston Marathon — a race that saw me collapse at the finish line and put me in the medical tent — I slept poorly for two days because everything hurt from the eyebrows on down.

But you don't need to go full CrossFit to get sleep benefits. Reid's study of older adults had them starting with just 10-15 minutes of exercise per day, four days a week, at a moderate level, and ramping up to 75 percent of maximum heart rate for 30 to 40 minutes four times a week after five weeks for the duration of the 16-week study. It made the participants' lives better across myriad parameters beyond sleep quality compared with those who only received sleep-hygiene education.

I'll argue that the modest time commitment it takes to exercise is more than compensated for by the increase in productivity — except when it comes to reading in bed. It takes me months to finish a book that way.

Fell is a certified strength and conditioning specialist and owner of bodyforwife.com.